Abstract This application is in response to PAR-15-326 to facilitate the PI's entry using neuroimaging in opiate addiction, thereby expanding her prior research expertise into the field of opiate research. The PI will work with her collaborators to develop expertise in diffusion tensor imaging (DTI) technique to conduct a multi-method assessment to better understand brain structure-function relationship in prescription opiate users. Opiate overdose, specifically the prescription opiate overdose has taken the form of epidemic in the U.S. The goal of this proposal is to provide a multimethod assessment of structural and functional brain changes within prescription opiate users' drug cue processing network (DCPN; implicated in drug seeking behavior) using functional magnetic resonance imaging (fMRI) and the tools of structural, functional and effective connectivity analysis. This is a proposal to collect the first structural, functional and effective connectivity data between the regions within the DCPN in prescription opiate dependents (PODs) and matched controls. If funded, this I/START grant will allow the PI to transition to the opiate addiction field. She will combine her existing neuroimaging knowledge with new knowledge on DTI technique that she plans to gather during this grant period, and finally would like to apply her expertise into the new field of prescription opiate. By using the voxel based morphometry (VBM) and DTI techniques, the PI and her collaborators will explore group differences in structural gray matter volume and density (VBM) and white matter connectivity (DTI) in regions within the DCPN. The functional connectivity (using a resting state task) between the regions within the DCPN and the effective connectivity (using a prescription opiate cue exposure task) between the regions within the DCPN will be compared between the POD and control groups (Aim 1). Sex differences in brain structure and function within the DCPN between the POD and control groups using VBM, DTI, a resting state task and a prescription opiate cue exposure task will be explored (Aim 2). Thirty PODs and 30 age and gender matched controls will be recruited. Each participant will take part in one imaging session and will complete alcohol and other drug use questionnaires. During the resting state scan, participants will fixate on a cross. During the prescription opiate cue exposure task, participants will view prescription opiate related and neutral visual stimuli and will provide craving ratings. During DTI Imaging, participants will view a fixation cross. For the VBM analysis, a MANCOVA will be performed between the groups with gray matter volume (or gray matter density) as a repeated factor. For each analysis, factor scores will be derived. Independent sample t-tests will then be conducted between the PODs and controls on factor scores (DTI, functional, effective connectivity). Correlations between craving ratings and each factor score in PODs will be calculated. A separate 2 (sex) x 2 (group) ANCOVA will be conducted for each factor score probing for sex by group interactions. This project may help for future development of brain-based algorithms to optimize treatment of individual PODs.